The present invention relates to agricultural implements and machinery, and more particularly to a novel method and apparatus operable for transplanting plants automatically, such as seedlings from a seedling tray into preselected rows in a field.
The process of transplanting row and vegetable crops has gained popularity in recent years and various attempts have been made to streamline the transplanting and automate the process. The use of transplanting, i.e. growing seedlings in a greenhouse and then transplanting them to a field, has been found to be an efficient agricultural process for crops such as celery, lettuce, cauliflower, peppers, tomatoes, broccoli, brussel sprouts, beets, asparagus, etc. Some of these crops, such as lettuce and celery, are "high density" crops, i.e. anywhere from 30,000 to 45,000 plants per acre are planted, and it should become apparent that an extremely efficient agricultural machine is necessary to accomplish such high density planting.
There have been many proposals in the prior art for agricultural machines designed for transplanting purposes. Exemplary of such devices are the transplanters set forth in Huang, U.S. Pat. No. 3,712,252 and Huang et al., U.S. Pat. No. 3,446,164. In the '164 patent, the transplanter disclosed is a wheeled device operable for being pulled behind a tractor and includes a so-called automatic transplanting device, of the gravity type, which regulates the velocity of impact between a plant and the earth. The transplanting device is constructed with blade-like openers for creating a furrow in the soil for receiving plants and it is provided with a bore operably connected to what are referred to as vacuum sleeves for directing plants from a tray mounted on the device downwardly through the vacuum sleeve and into the furrow created by the aforementioned openers.
Another type of plant setting machine is disclosed in Burrows, U.S. Pat. No. 2,804,033 which includes a device having fingers which automatically open and close to receive a plant at one position of an cperating cycle and to open at another portion and deposit the plant. A furrow opening device, of conventional shoe construction, is used in conjunction with the setting fingers to create a furrow for the plant to be deposited. After the plant is set in place, a control valve, responsive to the operation of the setting fingers, is actuated to release water into the furrow for irrigating the plants during transplanting intervals.
Another example of a transplanting method and apparatus is set forth in Talbott, U.S. Pat. No. 4,182,247. The method and apparatus set forth in that patent contemplates the use of a vehicular frame having a carriage which is reciprocally shiftable relative to the length of the frame. There are incorporated a plurality of fluid dispensing nozzles on the carriage for injecting fluid jets in the ground to form crop-receiving cavities. The vehicular frame is pulled behind a tractor and the carriage is maintained substantially immobile relative to the ground during fluid injection while the frame is continuously advanced. After the cavities are formed, seedlings are manually introduced thereinto. Seats are arranged on the frame and a support for holding a seedling tray is also mounted proximal to the seats. An individual or individuals are seated on the frame, and during transport over a field to be transplanted, seedlings are removed manually from a tray and placed into the cavities which have been formed by the fluid dispensing nozzles.
The use of fluid injection to create crop or plant-receiving cavities, as set forth in U.S. Pat. No. 4,182,247 described above, has been found to be very advantageous. However, that patent does not set forth a method and apparatus which is totally automatic for transplanting crops. One of the problems resides in the fact that it has been found problematical to develop a system which will gently handle seedlings grown in seedling trays to place them into the ground. The preferred method would be to provide some type of transplanting device which would be operable for removing seedlings from a seedling tray and without damage to the root system or soil medium, place the seedling into a crop-receiving cavity.
Accordingly, it is an object of the present invention to provide a method and apparatus for transplanting crops which contemplates providing a transplanting apparatus having means for receiving trays of seedlings, direct from a greenhouse, and sequentially displace seedlings from those trays into selected crop rows via an automatic mechanical process.
It is another object of the present invention to provide a method and apparatus which utilizes a plurality of fluid dispensing means mounted on the transplanting apparatus selectively operable for directing fluid against the ground to form a plurality of laterally spaced-apart plant-receiving cavities. The fluid dispensing means are positioned in advance of a carriage means which is provided on the apparatus for receiving a plurality of seedling trays. The carriage means is also provided with plant setter means which are selectively operable for engaging selected seedlings and displacing them substantially vertically downwardly from a selected cell in a seedling tray into a plant-receiving cavity.
It is another object of the present invention to provide plant setter means which are operable for holding and controllably guiding a seedling from a seedling tray in a substantially vertical position for placement into a plant-receiving cavity. To this end, the present invention contemplates that each plant setter means will include an impaling means which is slidably received within a pusher means. The impaling means is directed into the soil system of a seedling to a predetermined depth for holding the seedling substantially vertically during a transplanting step. The pusher means includes a foot which engages the top of the seedling for urging it downwardly through its cell in the seedling tray.
Still another object of the present invention is to provide the fluid dispensing means, as described above, with a pair of spray nozzles for creating plant-receiving cavities having a mixture of mud and water. This is accomplished by providing a first spray nozzle which directs a fluid jet, such as a water jet, into the soil to cut a slot. That spray action is immediately followed by another spray nozzle which sprays water in a fan-like action to gently cave in the soil around the previously cut slot so as to create an opening or cavity in the ground containing a mixture of water and soil. This mixture is very conducive to receiving a seedling in a low-impact and non-shocking manner.
A still further object of the present invention is to provide a method and apparatus, as described above, in which the transplanting apparatus is provided with an indexing means selectively operable for sequentially laterally displacing the seedling trays relative to the transplanting apparatus. Each of the seedling trays is provided with a plurality of rows, and the plant setter means are staggered so as to coact with only a preselected row of the trays. The indexing means is operable for indexing the trays laterally across the machine, one cell per planting cycle, to a position beneath a plant setter means for the seedling in a cell to be dispensed or guided into a preformed plant-receiving cavity.
A further object of the present invention is to provide a seedling tray construction which includes cell dimensions configured for receiving soil material and a seedling to enable growth in a greenhouse but which also will permit the plant setter means to urge the seedling downwardly through a cell. In order to construct such a seedling tray, and one which will also be operable for indexing as described above, the present invention contemplates that the cells will have open tops and bottoms, with the dimensions of the top being only slightly greater than those of the bottom, i.e. 3/4 inch square on the top and 11/16 inch square on the bottom. Further, the seedling trays are provided with indentations which coact with an indexing means for permitting the trays to be selectively shifted or indexed.
These and additional objects and advantages of the present invention will be more readily appreciated after a consideration of the drawings and the detailed description of the preferred embodiment.